return from class?

[Jacek Popławski]

I use python and Tkinter.
I have "Add product" window:

NAME: [.entry.]
PRICE: [.entry.]
PRODUCER: [.label.] [Button]

When I click "button" - another window should open, with Listbox of
corporations, then I should select on corporation and click "OK" in that
window, then id of that corporation should be returned to this "add product
window".
So I created other class - with listbox, scrollbar, button, but I don't know
what should I write in command function for button "OK". Class instance should
be destroyed and return value - id of selected corporation. How to do this?

-- 
She never breaks into the conversation  He seems to be the reason why she lives
She tries to be the perfect kind of stranger                
But we always seem to love the most                         
The ones who never give                "Between Two Hearts" - Ronnie James Dio